The invention relates to an arrangement for the grouping into rows of products of a batch, particularly on a high-speed conveyor belt.
More particularly, the invention relates to an arrangement for the grouping of several products in the form of batches, wherein the products are transported on at least one conveyor belt which runs in a longitudinal direction from an upstream entrance zone to a downstream exit zone, at a determined speed called the traveling speed, wherein the products are placed longitudinally on the conveyor belt in at least one first line of products and one second line of products parallel to the first line and comprising respectively products which, from one line to the other line, are offset longitudinally from one another by at least one upstream spacing, and comprising phasing means which, arranged on the path of the products between the entrance zone and the exit zone, are capable of forming batches made up by the grouping of at least two products and in a transverse row, the phasing means comprising at least one phaser which comprises at least one stop operated successively between:                at least one engaged position in which the stop is interposed, by contact, in front of a product of one of the lines for the purpose of decelerating it until it is joined by at least one other product situated immediately upstream on the other of the lines, and        at least one retracted position which makes it possible to let the previously-formed batch to continue its movement downstream at the traveling speed.        
This type of arrangement is used in installations for the packaging of products, for example in installations comprising a conveyor line which transports the products from a boxing machine, the boxing machine stacking the batches of products into packaging boxes or cartons.
The conveyor line usually comprises, upstream of the boxing machine, a conveyor belt which transports the products on one or more lines, with a determined spacing between two consecutive products, up to a grouper comprising a series of movable transport cavities.
The grouper has, facing the conveyor belt, at least one empty cavity provided to receive a determined number of products which are stacked in the cavity in order to form a batch.
When a batch is made up in the cavity, the latter is moved one notch in order to allow the grouper to present a new empty cavity facing the conveyor belt.
The cavities are therefore offset progressively, usually notch by notch, which makes it possible to transport the batches of products up to the boxing machine.
To facilitate and accelerate the filling of the cavities, it is known practice to make up the batches of products upstream of the grouper, by means of a device comprising means for phasing the products, also called a “phaser”.
According to a first solution, it is known practice to produce such a phaser by means of several successive conveyor belts, called rate-regulator conveyor belts, which operate at different traveling speeds.
In this type of phaser, the products arrive placed in lines, via a first conveyor belt, on an acceleration upstream conveyor belt operating at a traveling speed greater than that of the first conveyor belt.
The upstream conveyor belt transports the products to an intermediate deceleration conveyor belt.
The products are held down and retained on the intermediate conveyor belt by means of a lower suction device.
The intermediate conveyor belt progressively offsets each product forward until a rowed batch comprising at least two products grouped one beside the other is made up on the intermediate conveyor belt.
When the batch of products is made up, the traveling speed of the intermediate conveyor belt increases so as to transfer the batch to a downstream conveyor belt which operates at a traveling speed similar to that of the upstream conveyor belt.
The acceleration of the batch of products when it is transferred from the intermediate conveyor belt to the downstream conveyor belt limits the overall speed because, as it is too high, it then causes a movement of one or more products that is likely to disorganize the batch.
This type of phaser is also unsatisfactory because it requires the use of several conveyor belts placed end-to-end, which is particularly detrimental to the longitudinal space requirement of the installation.
The regulation of the speed of the various conveyor belts and the length of these conveyor belts are consequently calculated for a determined type of products and of batches so that it is necessary to develop a new phaser when the length of the products or the number of products per batch is for example modified.
In addition, the suction device does not work for certain types of products, which limits the scope of application of this phaser.
By its design, a phaser according to this first solution therefore does not allow the processing of products at very high speed.
According to a second solution, for example from document U.S. Pat. No. 4,892,181, an arrangement is known for the grouping of several products into rows.
In this document, the phasing means are in particular suitable for decelerating one or more products transported on a conveyor belt so as to form a transverse row from at least two products belonging to two lines that are parallel and initially offset longitudinally from one another.
However, the phasing means according to this document are not suitable for placing in rows products comprising only a reduced upstream spacing because the decelerating distance is very short.
Therefore, it is not possible to carry out a treatment of products at very high speed, particularly at speeds of more than 900 products per minute.
This is one of the reasons for which the applicant has proposed in French patent application No 0550528 lined on 28 Feb. 2005 (not published), a new phaser design constituting a solution that is simple, economic and effective that makes it possible to remedy the disadvantages of the phasing means according to the prior art.
This application No 0550528 relates to an arrangement like that described above, comprising a phaser which is arranged between the entrance zone and the exit zone of a conveyor belt to carry out the grouping “in columns” of products so as to make up batches from several products traveling in a single longitudinal line with a determined upstream spacing.
For this reason, the phaser comprises at least one retractable stop that is capable of being operated respectively between:                at least one engaged position in which the stop is interposed, by contact, in front of a first product of the line in order to decelerate it until this first product is joined by at least one second product which is situated immediately upstream in the line of products, in order to make up a first batch formed of the grouping into a column of two products aligned longitudinally one behind the other.        at least one retracted position which makes it possible to let the previously constituted batch continue its movement downstream at the traveling speed.        
According to the teachings of this document, such a phaser is used to make up a succession of batches that are each formed of at least two products grouped longitudinally one behind the other, that is to say of products aligned so as to form a column extending in the longitudinal direction of conveyance.
However, the make-up of such batches called “in a column” is not suitable for all applications, for example when the boxing machine stacks the batches of products into packaging boxes or cartons in a different orientation or else when the orientation is imposed by the shape of the product.
Therefore, by opposition to the batches of products grouped longitudinally “in a column”, there are batches of products grouped “in a row” that are made up of products grouped transversely one beside the other, that is to say placed head-on substantially on one and the same line.
Specifically, the rowed groupings of the products of the batches are for example preferred when the products have an oblong shape, longer than they are wide, and when they are also oriented on the conveyor belt in the lengthwise direction in the longitudinal direction of travel from upstream to downstream.